1. Field
The present invention generally relates to techniques for characterizing the performance of a computer system. More specifically, the present invention relates to a method and an apparatus that detects the presence of constrained motion, such as “rattling,” in one or more components in a computer system.
2. Related Art
Many new higher density disk drives have smaller track sizes and tighter tolerances to increase their storage capacity. Unfortunately, smaller track sizes and tighter tolerances make such disk drives potentially more sensitive to vibrations during operation of the computer system. Typically, manufacturers will design computer systems so that any potential structural resonances fall outside the expected range of vibrations generated by components in the computer system. Additionally, manufacturers often use isolation and damping methods to control vibrations that are generated within problematic frequency ranges. However, these isolation and damping methods may lose their effectiveness as a computer system ages. Furthermore, various factors such as: misassembly of parts, failure to meet manufacturing tolerances, servicing imperfections, aging of materials, and environmental conditions can lead to the creation of new vibration modes or the worsening of existing vibration modes through constrained motion of components in the computer system. (This constrained motion is in some cases referred to as “rattling.”) In particular, vibration modes generated by constrained motion of a component can generate a vibrational spectrum in the computer system that can result in degradation of the performance of disk drives. For example, the throughput of some disk drives may be more susceptible to degradation due to high frequency vibrations such as those that can be generated by some constrained motions of a component.
Hence, what is needed is a method and system that detects the presence of constrained motion in one or more components in a computer system without the above-described problems.